Truck bed



FIG. 1 is a top rear perspective view of a truck bed showing my new design, it being understood that the broken lines are for illustrative purposes only and form no part of the claimed design;

FIG. 2 is a side elevation view thereof, the opposite side being a mirror of that shown;

FIG. 3 is a rear elevation view thereof; and

FIG. 4 is a top plan view thereof.

The front of the truck bed is understood to be flat and unornamented. 

The ornamental design for a truck bed, as shown and described. 